Re: AW: Colibri imx8qxp: Missing kernel boot module

[Julien Grall <julien@xxxxxxx>]

On 01/09/2020 15:16, Daniel Wagner2 wrote:
> Hello,
Hi Daniel,

> > On 22/08/2020 13:00, Daniel Wagner2 wrote:
> > > > > > > > > > On 10/08/2020 16:32, Daniel Wagner2 wrote:
> > I am not entirely sure why yet. Do you mind to enable earlyprintk for your
> > platform? With that you should be able to get more information about the
> > list of modules discovered.
> I didn't manage to enable earlyprintk.
> But I enabled kconfig "Developer Checks": "Verbose debug messages" and
> "Devicetree debug messages" and put some extra printks in the Xen Source and
> was able to locate the problem.
>
> When parsing the fdt, the memory@80000000 node throws an error, which stops
> the parsing before the /chosen node was found and so no kernel boot module
> was found for dom0.
>
> I bypassed this by putting the /chosen node at the top of the fdt, so that
> module@0 gets parsed before the functions arrives at the memory node. After
> this change, Dom0 was successfully booted by Xen.
>
> I have created a pastebin https://pastebin.com/JBjKNvPP for future
> reference.
> At pastebin line 215 Xen already found the kernel boot module.
> So I put
> "boot_fdt_info(device_tree_flattened, fdt_paddr);"
> in start_xen (arch/arm/setup.c) after the
> "console_init_postirq();"
> call, so tha the function is run a second time, but this time the outputs
> are shown in the bootlog (starting pastebin l. 247).
> Starting at pastebin line 337, parser arrives at memory node.
> Line 349 is what is specified in the fdt (which I copy here for reference)
>
> memory@80000000 {
>         device_type = "memory";
>         reg = <0x00000000 0x80000000 0 0x40000000>;
> };
>
> The first bank found (l. 349) is the one from the fdt node. I am not sure
> where the second bank (l. 350) comes from. The the second bank's size=0 ist
> what causes the parse to fail and will Xen prevent from finding the boot
> kernel for dom0 if the /chosen node comes after the memory node in the fdt.
Thank you for digging through the problem. I find a bit odd that Xen 
discover a second bank. It might be possible we don't parse the 
Device-Tree correctly.
I wasn't able to find the node in the device-tree you provided in the 
initial e-mail. Would you mind to post the full device-tree?
Cheers,

--
Julien Grall